The variations in the electrophoretic patterns of total eye-lens proteins from M, furnieri determined by genetic differences between individuals that occupy the region between Cabo Frio (23ºS) and Chui (33ºS) were identified. Four types of patterns were characterized and the frequencies of occurrence of specimen carrying each type in the specie's populations I (23º-29ºS) and II (29º-33ºS) were analized. The results obtained, together with previous knowledge, allow some conclusions and hypothesis: population I is homogeneous, consisting of 99,1% of type I individuals and 0,9% of type II individuals, which indicates reduced genie flow from population II to I; population II is not homogeneous, being composed of 73,7% of type I individuals, 103% of type II, 12,7% of type ffl and 33% of type II-III; besides the considerable genie flow from population I to II, there also must exist a flow from the probable population(s) living along the Argentine and Uruguay coasts; in this way, population II would not base the "status" of population.
Micropogonias furnieri; Sciaenidae; Electrophoresis; Eye-lens; Proteins; Populations; Southeastern-south coast